I have used blackhole/razor for quite some time but found it to be disappointing. I am totally in love with "ASSP" or Anti-Spam Server Proxy. The project page is at http://assp.sourceforge.net . As someone who gets 150-200 spams a DAY, this has cut it down to 3-4. It's a Bayesian filter with tons of cool features like auto-whitelist and web-based config. It can even run on the same server as your MTA, just change your SMTP service to use something other than port 25, then have ASSP run on port 25. I highly recommend this software.
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I have used blackhole/razor for quite some time but found it to be disappointing. I am totally in love with "ASSP" or Anti-Spam Server Proxy. The project page is at http://assp.sourceforge.net . As someone who gets 150-200 spams a DAY, this has cut it down to 3-4. It's a Bayesian filter with tons of cool features like auto-whitelist and web-based config. It can even run on the same server as your MTA, just change your SMTP service to use something other than port 25, then have ASSP run on port 25. I highly recommend this software.